Specialised cable has to be installed, existing cable feed split, & signal levels balanced at the cabinet. Then you get the box set up & in a state where you know its working. £50 is not bad for 2 hours of a qualified techs time. Getting someone out to add a twin feed from a Sky dish to an additonal box would cost you a similar amount.
Cable customer since 1993. Services: FH TV, Sky Sports & Movies (2xV+), Talk Unlim Telco, VIVID 100, Virgin PAYG Mobile